And at least with renewables the starting energy arrives free in the UK so it's a lot less important if 80% is not used. Compare that with hydrocarbons that have to be bought from (or at least have the marginal price set by) Russia and/or the Middle East. We've already seen how volatility from Russia can eg push unsubisidised gas prices over £1/unit, do you have a plan to ensure peace in Russia and the Middle East?
Trouble with synthetic fuel is that it combines the inefficiency of hydrogen production with the inefficiency of ICE combustion. And all that inefficiency ensures it will always be relatively expensive compared to batteries. There will be a handful of applications where the energy density is going to be crucial - heavy aviation is likely one of them but we're already seeing all-electric light aircraft and it looks like that may extend into some smaller passenger planes. But since you like system thinking,
try this (it's from 2017 so the EV numbers are rather out of date, EV's are now in the mid-80s% rather than the 75% implied here) :
Volatility in Russia is not the cause of pushing up energy pricing. Especially when 80% of what we pay is tax and we pay huge levees and subsidies for renewables - if renewables are so cheap then why are we paying huge subsidies and levee's? The energy market has always been volatile and we've managed perfectly well over the years and energy prices have continued to trend down over time, until recently. The US has reduced its reliance on importing energy and its energy prices have plummeted as a result. We're moving in exactly the opposite direction, relying more and more on energy imports.
Our lack of energy independence is what is pushing up pricing and the fact politicians wont leave the energy markets alone and keep intervening and cocking it up making it more expensive for everyone. We have the capacity to be completely energy independent for hundreds of years. We are a very unusual country in the world...one of the few that has the capacity to be 100% energy independant. We have deliberately chosen not to be and have decided to reduce our overall generating capacity and import more and more from Norway (100% renewable), France (about 60% renewable/nuclear) and the Netherlands (still mostly Gas imported from Norway and ME and not so long ago Russia), and LNG from the Middle East, and converting old Coal powered stations to wood pellets....imported from Canada!!! (cant make this stuff up!!). And we pat ourselves on our backs telling ourselves we're reducing CO2 emissions and wag our fingers disapprovingly at other nations when all we're doing is offshoring it between the way we generate power, import it and with massive de-industrialisation, which is condemning the UK to a future of decline. So yay for us!! We're a net importer of energy and importing more and more of our energy needs and are becoming more exposed to international events...and cyber attacks, not less. Look around the world at those nations that are net importers of energy...not sure you'd want to live in any of those.
You don't need to create hydrogen to make sustainable fuels, but sustainable fuel production is very electricity hungry, as is battery , solar panel and wind turbine manufacture, but so what. We have an abundance of energy around us...more than we can use or will ever need so can stomach inefficiencies and renewables are no more efficient than fossil fuels....There are massive inefficiencies in all of this stuff.
So everything involving the conversion of energy is inefficient at some point in the chain, but it matters not when it comes to making sustainable fuels....because all that energy can be generated cleanly and sustainably by nuclear and that energy from renewables that you're already dumping...far better way to buffer energy than batteries. Batteries are just crap precisely because of their energy density....and when you take into account making the infrastructure associated with ICE redundant overnight and having to replace it with brand new massive levels of eyewateringly expensive (i.e. unaffordable) and resource hungry infrastructure to electrify everything, then you're just digging deeper into that CO2 debt/deficit not to mention making us politically more exposed to China, because China builds most of this stuff and builds it from.... dirt cheap energy generated mostly from coal. So worried about a volatile world? then why jump out of the frying pan and into the fire?
Energy density trumps efficiency every time. There are no transformative battery technologies coming any time soon, small nip and tuck improvements here and there, but nothing that will improve energy density anywhere near the level it needs to be. When a battery far is reduced to the size of a truck then we might be getting somewhere, but that ain't happening, not this century anyway. Don't believe the media on new battery technologies any more than their suggestions we're on the brink of nuclear fusion...every year we're just a decade away!